-Mountain castle with brick wall at beautiful valley-

Overview

Brief History

Ogura castle (小倉城) is located at a peninsular like long and narrow hill formed by U letter shaped curving Tsuchi-gawa river to Tokigawa town in the western part of Hiki providence of Saitama prefecture. Tsuchi-gawa river flows from eastern edge of Chichibu mountains passes Ogawa town and enters into hills between Ogawa town and Ranzan town. At this point Tsuchi-gawa river forms beautiful valley at the below of Ogura castle, and it is called as Ranzan Valley comparing with Arashiyama Valley of Kyoto city.Today Ranzan Valley is covered with beautiful red leafs in autumn, but of course Ogura castle was not built for leaf peeping. Western half of Hiki providence is a hilly area consist of three valley, it means current Ogawa area at upstream of Tsuchi-gawa river, Tokigawa area at the source of Toki-gawa river, and Ranzan area at the merging point of these two river. Ogura castle exactly stands at the center of these three valleys, and it was a good place to manage the western part of Hiki providence.

Mysterious origin of Ogura castle

Same as neighbor castles such as Sugiyama castle or Sugaya Castle, Ogura castle did not have record on its history. It is said that this castle was built by Ueda clan, the important retainer of Hojo clan resided at Musashi Matsuyama castle (Saitama prefecture) which locates about 10 kilometer east from Ogura castle, but also said that the builder was Toyama clan, another important retainer of Hojo clan.It was recorded that Ueda clan had the territory in Ogawa town and Tokigawa town at the west from Ogura castle, and also served as the commander of Musashi Matsuyama castle at the east. On the other hand, Toyama clan was deputy commander of Edo castle at Tokyo metropolis, and might have held territory around there. Considering this Ueda clan seems to be the commander of Ogura castle but not decisive.

History of Ueda clan

Ueda clan was said as a descendant of seven local Samurai croups at Musashi province, and emerged as an important retainer of Ogigayatsu Uesugi clan in the latter half of 15th century. It is said that Ueda clan was originally a local lord at Sagami province (Kanagawa prefecture) and later moved to Hiki providence under the order of Ogigayatsu Uesugi clan, and lack of record or tradition of the owner of the castles around the providence might stem from this fact.In the former half of 16th century, Ueda clan held Musashi Matsuyama castle and resisted against the expansion of Hojo clan in cooperation with Sukemasa Ota (1522-1591) who was the commander of Iwatsuki castle (Saitama prefecture). Later Ueda clan turned to Hojo clan with Musashi Matsuyama castle, but Musashi Matsuyama castle was deprived by Kenshin Uesugi (1530-1578) who was the warlord of Echigo province (Niigata prefecture) and intruded into Kanto plain in 1560. In 1563, Hojo clan recovered Musashi Matsuyama castle from Uesugi army. Ueda clan was appointed as the commander of Musashi Matsuyama castle, and held Hiki providence as territory under Hojo clan. As Hiki area is a long and narrow area spreads east and west, and Musashi Matsuyama castle existed at eastern edge, Ueda clan built the network of castles to govern their territory. Among them, Ogura castle might be the center connected eastern half and western half of the territory.

Structure of Ogura castle

Ogura castle is built at the root of peninsular shape hill of 600 meter long and 200 meter height spreads from southwest to northeast, about 70 meter tall from hillside. As eastern slope is rather gentle and had a flat space before the river suitable for castle town, the plan of the castle faces east.Hilltop area consists of large two terraces, it mean central area and secondary area. Central area of the castle is a trapezoid shaped area of 80 meter long and 40 meter wide, which is separated into upper half and lower half. There are three gates at north, south and east of the area, all of which were decorated by stone walls.At the south of central area, ahead of deep dry moat, secondary area which is a long and narrow rectangular one of 80 meter long and 30 meter wide exists. As southward of the castle is expected battle front which is connected with backside mountains, this secondary area is built as a front fort securely protected by tall clay wall. Furthermore, ahead of another deep dry moat, buffer area is built toward south.At the east of central area, third area which is a small trapezoid shaped terrace is built on the ridge spreads toward east. This ridge is relatively gentle and might be used as another approach route to the castle, and also faced to castle town located at hillside. Because of this, both for the purpose of defense and decoration, stone walls which is over 3 meter high and 50 meter long is built at three lines of the area. Other than these major areas, many small terraces were built surrounding core areas, and many dry moats were made to obstruct the enemy.

Stone walls at Ogura castle

As above, rarely seen in mountains castles under Hojo clans, Ogura castle proactively used stone walls at various part. Hojo clan started to use stone walls for their castles such as Hachioji castle or Hachigata castle at their final stage, and Ogura castle might precede this usage. Furthermore, stone walls built by Hojo clan mainly used round shaped stones, but stone walls of Ogura castle is built by piling up thin small pieces, like brick walls. This kind of stone walls is frequently seen at the castles of Ogasawara clan in Shinano province (Nagano prefecture), but no other example in Kanto region. As Ogura castle is built digging rocky hills, these stone walls was built using surplus stones generated from construction, with limited building technology. Considering large size structures with advanced clearly intended plan, Ogura castle might be built or significantly reformed in the latter half of 16th century at one time.

Afterward of castle

Ueda clan served as the commander of Musashi Matsuyama castle and governed Hiki providence over 20 years, but finally disappeared from history at the fall of Hojo clan by Odawara campaign of central ruler Hideyoshi Toyotomi (1537-1598) in 1590. Ogura castle might be disposed at this time and remained forgotten in the forest. As the castle was not involved in development, today most part of the castle well remain on the hill, and is nominated as national historic site along with neighbor Musashi-Matsuyama castle, Sugiyama castle and Sugaya castle. Rich remnants including stone walls and quite limited information attracts the imagination of visitors on the origin of the castle.